IBMs Customer Information Control System CICS Art Hendela

IBM’s Customer Information Control System, CICS Art Hendela, President Hendela System Consultants, Inc. Little Falls, NJ 1 -973 -890 -0324 WWW. HENDELA. COM art. hendela@hendela. com Your Web Database Experts

What is a Transaction? • A transaction has four properties: It is “Atomic, Consistent, Isolated, & Durable”. • Atomic - A unit of work that succeeds or fails. • Consistent - System restored to a constant state after completion. • Isolated - one transaction does not impact another, even if done at the same time. • Durable - A committed transaction is permanent. http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS History • 1968 - Package developed by Michigan Bell and IBM on OS/360 • 1971 - CICS available for DOS & DOSE • 1973 - Development moved to Hursley, England • 1987 - CICS/VM introduced • 1992 - CICS/400 version for AS/400 • 1996 - CICS Web Interface Product http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Hardware & Operating Systems • • • IBM z. Series 900 - z/OS IBM S/390 - OS/390, MVS, VSE IBM AS/400 - OS/400 IBM RS/6000 - AIX (Unix) PC Server - Windows NT/2000, OS/2 The most popular is the S/390 using OS/390 or MVS http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Programming Languages • • • Assembler COBOL PL/I Rexx C/C++ JAVA http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Organization • • • CICS Management Services Data Management Services Application Programming Interface Basic Mapping Support Terminal Control Services http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Service Diagram VSAM File Control DB 2 SQL IMS DL/I CICS OS/390 Application Programming Interface Application Program Terminal Control Basic Mapping Support Maps (VTAM, SNA, TCP/IP) Terminal User http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Program Invocation User Enters TRANS-ID CICS loads program into memory/ starts program CICS finds TRANS-ID in PCT to get program name CICS finds program name in PPT CICS runs program in address space TRANS-ID = Transaction Identifier PCT = Program Control Table PPT= Processing Program Table http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Example - Screen 1 http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Example - Screen 2 http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Example - Screen 3 http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

CICS Example - Screen 4 http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

Summary • CICS grew from the need to handle interactive transactions • CICS operates on many different IBM compatible hardware platforms using a variety of languages. • CICS uses Service programs to control execution and use of system resources. • A CICS user sends a TRANS-ID to begin the program execution. http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

Glossary • • • • • [Ankrum] ACID - Atomic, Consistent, Isolated, Durable: transaction properties. BMS - Basic Mapping Support: For definition and access to formatted screens. CICS - Customer Information Control System. CMS - Conversational Monitor System: An interactive subsystem for VM. DB 2 - Database 2, IBM’s relational database manager. DL/I - Data Language / I: General purpose database control language. DOS - Disk Operating System: An early IBM operating system for small mainframes or the original operating system for IBM compatible PCs. IMS - Information Management System: IBM Product with an OLTP and hierarchical database manager. MVS - Multiple Virtual Storage: Top of the line IBM operating system before OS/390. OLTP - On-line Transaction Processing. OS/390 - Open System 390: latest operating system for IBM System/390’s. SNA - System Network Architecture: IBM’s proprietary network protocol. SQL - Structured Query Language: interface to access relational databases. TCP/IP - Transmission Control Protocol/Internet Protocol. VM - Virtual Machine: IBM Mainframe operating system to allow multiple operating systems to run on one machine simultaneously. VSAM - Virtual Storage Access Method. VTAM - Virtual Telecommunications Access Method. Additioanl definitions may be found at: http: //www. transarc. ibm. com/Library/documentation/websphere/WASEE/en_US/html/glossary/cicsglos. htm http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization

References • • • Antrim, T. Scott, “The Evolution of CICS 30 Years Old and Still Modern. www. cobolreport. com/columnists/tscott/part 1. html - part 4. html, May, 2001. Comaford, Christine, “Managing Transactions is a Serious Business”. PC Week, March 20, 1995 12(11), pg 19(1). Donofrio, Phyllis. “CICS-A Programmer’s Reference”, Mc. Graw-Hill, 1991. Horswill, John & Hursley CICS Development Team, “Designing & Programming CICS Applications”, O’Reilly, 2000. Hudders, Eugene S. “CICS-A guide to Internal Structure”, John Wiley & Sons, 1994. IBM, “CICS”, http: //www-4. ibm. com/software/ts/cics/, 2001. Lowe, Doug, “The CICS Programmer’s Desk Reference”, Mike Murach & Associates, 2 nd Ed, 1992. Menendez, Raul & Doug Lowe. “Murach’s CICS for the COBOL Programmer”, Mike Murach & Associates, 2001. Nusphere Tech Notes, “ACID Transactions” www. nusphere. com/products/library/acid_transactions. htm, http: //www. hendela. com Your Web Database Experts. Landing pages, Online Surveys, Search Engine Optimization